Which number doesn't belong? This lesson requires students to think critically as they determine which number is not a factor of a particular number. Teach it on its own or as support for the lesson Factors Over the Rainbow.
Students will be able to find all factor pairs for a given number.
Language
Students will be able to distinguish a factor from a non-factor and explain their reasoning using sentence starters and interactive supports.
Introduction
(4 minutes)
Ask students to turn to a partner and share their background knowledge on multiplication. Ask the following guiding questions to spark conversation: "What does multiplication mean? When do you need to multiply numbers? How do we show or represent multiplication?"
Listen in on students' conversations and have them share with the whole group some of their key points. Guide students to the understanding that multiplication is when you add a number to itself a certain number of times. Some ways we can show multiplication include arrays, repeated addition, equal groups of items, a multiplication chart, etc. Record students' ideas and important points from the discussion on the board.
Explain that today we will explore an important concept related to multiplication called factors.